Healthcare-associated infections (HAIs) have high morbidity and mortality in the neonatal intensive care unit (NICU). To accommodate the nursing shortage many health care facilities have increased their use of pooled staff and temporary agency nurses. Recent studies have examined the relationship between nurse staffing and adverse patient outcomes, and found correlations with certain nurse staffing parameters and risk of HAl, but to date none have been prospective or have examined the correlation between a number of staffing variables and HAl in high risk neonates. The aim of this competing supplement is to examine the relationship between nurse staffing and HAIs in neonates in the NICU. This is a prospective, correlational design using data being collected as part of a larger ongoing clinical trial to examine the effects of two hand hygiene regimes on HAIs in neonates in the NICU (1RO1NR05197, "Staff Hand Hygiene and Nosocomial Infections in Neonates", 2/1/01-1/31/03). Data collection began on March 1, 2001 at two, large NICUs in New York City. By 1/1/02 (data collection halfway point), >1,500 neonates and 115 nurses were enrolled, with a final sample size estimated to be about 45,000 nurse days and 52,000 neonatal days. Daily nurse staffing hours are being obtained from the nurse staffing office at each site and are sorted into the categories of RN full-time, RN part-time, full-time other, part-time other, patient care technician, pooled and agency. HAl data are being collected prospectively by an experienced ICP. Logistic regression with GEE modeling, adjusting for potential confounders such as hospital, patient acuity, nursing care needs (measured by Nursing Intensity Weights), season, use of invasive devices or prophylactic antibiotics, etc will be used to generate estimated relative risks for infection when various staff parameters are examined. [unreadable] [unreadable] [unreadable]